1. Field of the Invention
The present invention relates to a manufacturing method of an oxide semiconductor device, and more particularly, to a manufacturing method including forming an oxide semiconductor layer on an oxygen provider layer.
2. Description of the Prior Art
Because of the properties of low leakage current and high mobility, oxide semiconductor materials such as indium gallium zinc oxide (IGZO) are applied in thin film transistors (TFTs) of display devices and field effect transistors (FETs) of integrated circuits. However, the material and electrical properties of the oxide semiconductor layer tend to be influenced easily by the environment and the manufacturing process conditions. For IGZO, oxygen conditions such as oxygen deficiency and excess oxygen in IGZO play a crucial role in formations of shallow donor states and sub gap trap states, which largely affect the device characteristics. For example, if there are too many oxygen vacancies in an IGZO layer while some of the oxygen in the IGZO layer diffuses outward, the conductivity of the IGZO layer is enhanced and the IGZO layer may be converted from a semiconductor material into a conductive material. Therefore, it is important to protect the oxide semiconductor material from ambient influence so as to improving the stability and reliability of the oxide semiconductor device.